Rope-pull starter for internal combustion engines



Jan. 2, 1968 F. FEND 3,361,124

ROPE'PULL STARTER FOR INTERNAL COMBUSTION ENGINES Filed Nov. 15, 1965 2 Sheets-Sheet 1 AWE/W04 FRITZ FEND F. FEND Jan. 2, 1968 I ROPE-PULL STARTER FOR INTERNAL COMBUSTION ENGINES Filed Nov. 15, 1965 2 Sheets-Sheet 2 P W W FRITZ FEND United States Patent M 3,361,124 ROPE-PULL STARTER FOR INTERNAL COMBUSTIUN ENGINES Fritz Fend, Regeusbnrg, Germany, assignor to Fichtel 8; Sachs A.G., Schweinfnrt am Main, Germany Filed Nov. 15, 1965, Ser. No. 507,835 3 Claims. (Cl. 123-185) AESTRACT OF THE DISCLOSURE The rope of a pull-rope starter in an internal combustion engine is guided in a fixed path when tensioned, and is deflected from that path by a spring-loaded deflector member when slack. When the rope is tensioned, the deflector member is moved against the restraint of its spring, and the movement is transmitted by a linkage to a decompression valve on the engine to reduce the cranking effort, and also to a fuel injection pump or to a choke in the carburetor to enrich the fuel mixture during cranking of the engine by the pulled rope.

This invention relates to internal combustion engines, and particularly to rope pull starters for such engines, and to engines equipped with such starters.

Small internal combustion engines are commonly equipped with a manual starter having a drum connected to the crankshaft of the engine by a one-way clutch, a rope which is normally wound on the drum by a spring, and a handle at the free end of the rope. When the handle is pulled, the drum turns in such a direction that the rotary drum movement is transmitted to the crankshaft by the clutch. Under otherwise proper conditions, the engine is started thereby.

The number of additional operations to be performed to establish proper starting conditions varies with diflerent engines. It is often necessary to vent the engine cylinder initially to permit the rope to be pulled at all. It may also be necessary to provide fuel mixture to the engine, or to modify the composition of the fuel mixture for the starting period. Starting a small internal combustion engine may be difficult or even impossible if the several control steps are not properly taken or are not taken in the proper sequence.

The object of the invention is the provision of a ropepull starter for internal combustion engines which automatically adjusts the engine controls for proper starting conditions.

With this primary object in view, and such others as may become apparent hereinafter, the invention provides a rope operated starter for use in an internal combustion engine in which a pliable rope is wound on a drum so that the drum properly turns the crankshaft when the rope is unwound from the drum by pulling. The rope is held by a guide in a predetermined path by the pulling tension, and a deflector which is movable transversely of the path engages a portion of the rope between the drum and guide. A spring or the like urges the deflector to move transversely of the path in such a manner as to deflect the rope from its path, and the deflector is moved toward the path when the rope is tensioned. A link age connects the deflector to one or more control elements of the engine to be started in such a manner that the control element or elements assume proper starting positions when the deflector is moved into the aforementioned path by tension applied to the rope.

Other features and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following description of preferred embodiments when considered with the accompanying drawing in which:

3,361,124 Patented Jan. 2, 1958 FIG. 1 shows an internal combustion engine equipped with the pull-rope starter of the invention in fragmentary, partly sectional View;

FIG. 2 shows a detail of an engine equipped with a modified starter in elevation and partly in section;

FIG. 3 shows a detail of the engine of FIG. 1 in elevational section;

FIG. 4 illustrates a modified detail of the engine of FIG. 1;

FIG. 5 is a fragmentary plan view of the engine of FIG. 1.

Referring now to the drawing in detail, and initially to FIGS. 1, 3, and 5, there is seen as much of a small internal combustion engine as is necessary for an understanding of this invention. A cylinder 10 encloses a non-illustrated piston which drives a crankshaft 29 in a conventional manner. Starting of the engine is facilitated by a spring-loaded, normally closed decompression valve 9 on the cylinder head. The fuel supply system of the engine includes an auxiliary fuel metering and injection device best seen in FIG. 3. A piston 20 is slidably received in a cylinder 19, which is connected with a nonillustrated fuel storage tank by a suction line 22 equipped with a check valve 22', and with the cylinder 10 by a pressure line 21 having a check valve 21'. The check valves are arranged to permit flow from the fuel tank toward the cylinder 10 only. The rod 18 of the piston 20 is biased by a helical compression spring 23 to discharge fuel from the cylinder 19.

A drum 1, only partly visible in FIG. 1, is journaled on the crankshaft 29, but is largely concealed by a housing 1'. Wedge shaped recesses 30in the drum 1 near the shaft 29 contain respective rollers 31 which jointly constitute a roller clutch for transmitting movement from the drum 1 to the shaft 29 when the drum rotates clockwise, as viewed in FIG. 1. A starter rope 2 partly wound on the drum 1 in a conventional manner, not visible in the drawing, turns the drum clockwise when the handle 16 on the free end of the rope is pulled.

The structure described so far is at least in part conventional. The rope 2 is trained over a guide pulley 3 mounted on the engine casing 4 so that the pulley 3 and the drum 1 define a straight path which is assumed by the rope 2 when fully tensioned. The rope 2 is normally deflected from this path by a pulley 5 mounted on one end of a pull rod 7 whose other end is suspended from a helical tension spring 6 mounted on the engine casing 4. The spring 6 resists the movement of the deflector pulley 5 in a direction from the fully drawn position toward that indicated by broken lines in FIG. 1 when the rope 2 is tensioned, and returns the pulley 5 toward the fully drawn position when the tension on the rope 2 is relaxed.

The end of the rod 7 near the spring 6 is hingedly connected to one arm of a lever 8 which is pivoted on the cylinder 10 by a pin 8'. The decompression spring 9 is pivotally attached to the same lever arm nearer the pin 8 than the rod 7. The other arm of the lever 8 is linked by a pull rod 11 and associated pivot pins to one arm of a bellcrank lever 12 attached to the engine casing 4 by a pivot pin 12'. The other arm of the lever 12 abuttingly engages a disk 13 coaxially mounted on the piston rod 18 of the afore-described auxiliary fuel metering and injection device.

When the rope 2 is pulled in the direction of the arrow 17 to start the engine, the deflector pulley 5 moves toward the position illustrated in broken lines, the decompression valve 9 is opened to vent the cylinder 10, and thereby to reduce the resistance of the non-illustrated piston to rotation of the crankshaft 29, and fuel contained in the cylinder 19 is injected into the engine 3 cylinder 10 to enrich the fuel mixture provided by the normal fuel system, not itself shown.

When the tension on the rope is relaxed, the lever 8 is returned to the fully drawn position, whereby the decompression valve 9 is closed, and the continuing inertial rotation of the crankshaft 29, which carries a flywheel in the usual manner, not illustrated, causes the fuel mixture in the cylinder 10 to be compressed. The engine is started. A helical torsion spring 32 (FIG. interposed between the drum 1 and the engine casing 4 is tensioned by the pulling of the rope, and rewinds the rope on the drum 1 when the handle 16 is released.

The pull-rope starter shown in FIG. 2 differs from that illustrated in FIG. 1 by the lack of a guide pulley. The rope 2 passes through an aperture 4' in the casing 4 which performs the guide function, and whose edges are rounded to minimize wear of the rope 2. The defiector 5 is mounted on one arm of a bellcrank lever 14 attached to the engine casing 4 by a pivot pin 15. The other arm of the lever 14 is linked by the afore-described rod 7 to the controls of the engine not otherwise shown in FIG. 2. The lever 14 is pivoted in a plane parallel to the path of the rope 2 when the latter is tensioned.

FIG. 4 shows a modification of the apparatus of FIG. 1 in which the composition of the fuel mixture during starting is modified not by the supply of additional fuel but by a reduction in the amount of air in the mixture.

A rod 24 is longitudinally slidable on the engine casing 4 and carries a disk 13 for cooperation with the aforedescribed bellcrank lever 12. A choke flap 27 is mounted in the air intake duct 28 of the engine carburetor, not otherwise shown, on a shaft 26 and is connected by a linkage consisting of hinged members 24', 25, 25 to the rod 24. The helical compression spring 23 normally holds the choke flap 27 in the illustrated open position, and the air supply to the carburetor and the cylinder is throttled during starting when the movement of the deflector 5 toward the path of the tensioned rope 2 causes the lever 12 to rock against the restraint of the spring 23. The air intake duct 28 is opened again when the rope 2 is released.

If the engine to be started by the pull rope 2 is a diesel engine, the fuel metering device shown in FIG. 3 may constitute the main fuel injection pump which is further operated by conventional means, not shown, after the engine is started.

Other modifications and variations of the cooperation of a pull-rope starter with the control elements of an internal combustion engine will readily suggest themselves to those skilled in the art on the basis of the above teachings. It is therefore to be understood that the invention is not limited to the embodiments chosen for the purpose of disclosure, but may be practiced otherwise than disclosed, and is to be defined solely by the appended claims.

What is claimed is:

1. In an internal combustion engine, in combination:

(a) a crankshaft;

(b) a drum member rotatable about an axis;

(0) a pliable rope member wound on said drum member for rotating the same about said axis in a predetermined direction when said rope member is unwound from said drum member by applied tension;

(d) one-way clutch means interposed between said drum member and said crankshaft for transmitting rotation of said drum member in said predetermined direction to said crankshaft;

(e) cylinder means operable for rotating said crankshaft, said cylinder means including a cylinder member;

(f) guide means for guiding said rope member in a predetermined path when the rope member is pulled for said unwinding;

(g) a deflector member mounted on said cylinder means for movement transversely of said path and engaging a portion of said rope member intermediate said drum member and said guide means;

(h) control means movable for controlling operation of said cylinder means, said control means including fuel metering means for metering an amount of fuel and for injecting the metered fuel into said cylinder;

(i) linkage means connecting said fuel metering means to said deflector member for joint movement; and (j) yieldably resilient means permanently urging said deflector member to move transversely away from said path and thereby to deflect said rope member from said path.

2. In an internal combustion engine, in combination:

(a) a crankshaft;

(b) a drum member rotatable about an axis;

(a) a pliable rope member would on said drum member for rotating the same about said axis in a predetermined direction when said rope member is unwound from said drum member by applied tension;

(d) one-way clutch means interposed between said drum member and said crankshaft for transmitting rotation of said drum member in said predetermined direction to said crankshaft;

(e) cylinder means operable for rotating said crankshaft, said cylinder means including a cylinder member and'fuel supply means for supplying a mixture of liquid fuel and air to said cylinder member;

(f) guide means for guiding said rope member in a predetermined path when the rope member is pulled for said unwinding;

(g) a deflector member mounted on said cylinder means for movement transversely of said path and engaging a portion of said rope member intermediate said drum member and said guide means;

(h) control means movable for controlling operation of said cylinder means, said control means including means for varying the ratio of said fuel and of said air in said mixture;

(i) linkage means connecting said control means to said deflector member for joint movement; and

(j) yieldably resilient means permanently urging said deflector member to move transversely away from said path and thereby to deflect said rope member from said path.

3. In an engine as set forth in claim 2, said fuel supply means including a carburetor having an air intake duct, and said control means including a choke member mounted in said duct and connected to said deflector member by said linkage means.

RALPH D. BLAKESLEE, Primaly Examiner. 

